Operator&#39;s selective ringing-key for telephone systems.



PATENTED MAY 12, 19.

, R: H. MEiNSQNr 'OPERATOR'S SELSCIIVE EINGING K APPLICATION FILEDiWV.15.1904.

'mssv-zso. PATENTED MAY 12, 1908.

' I I R. H. MANSON. OPERATORS SELECTIVE RINGING KEY FOR TELEPHONESYSTEMS.

APPLICATION TILED NOV.15.1904.

2 SHEETSSHEBT Z.

WITNESTSES: INVENTOR am M UNITED sTATEs PATENT OFFICE.

RAY H, MANSON, OF ELYRIA, OHIO, ASSIGNOR TO THE DEAN ELECTRIC COMPANY,OF ELYRIA, OHIO, A CORPORATION OF OHIO.

OPERATQRS SELECTIVE RINGING-KEY FOB TELEFHONE SYSTEMS. v

I No. 887,260.

Specification of Letters Patent.

Patented May 12, mos.

Application filed November 15, 1904. Serial No. 282,857.

- T allwhom it may concern: i

Be it known that I, RAY H. MANsON, a citizen of the United States,residing at Elyria, in the county of Lorain and State of Ohio, haveinvented-certain new and useful Improvements in Operators SelectiveRinamg-Key's for Telephone Systems, or wluci the following is aspecification, reference behad therein to the accompanying drawthe sameline.

Briefly stated, my invention resides in a four arty selective key and.its connections, toget or with line arrangements cooperating therewith.

Heretofore, according to the best pracwith their ringers bridged andadapted to respond tocurrents of different frequencies, or

' having the ringers 'roundcd from opposite sides of the line an adaptedto respond to currents of opposite direction. Calling keys have beenprovided comprising double ele ments, first, the ordinary ringing keywhich puts generator to line and severs the cord circuit so as not toring back, and second, a special selective keyset usually with fourbuttons each corresponding to one subscribers position on t is line andeach adapted to connect a calling enerator to the princi a1 key contactsin the pro per manner to ca l the corresponding station. A catch hasbeen provided, or its equivalent, for holding down the key lastdepressed, so that the operator can ringagain if the subscriber does notat first answer, the necessity for remembering which key was used beingthus obvi- 'ated.

It is the object of my present invention to improve keys of this generaltype and their circuits, so as to simplify them and decrease the chancesof trouble. In the older type of keys there are many springs and manycontacts through which the talking circuit or ringing circuit must pass,some of these contacts being individual to each selective key,

and as in all series contacts, trouble with any one would disable thecircuit. Moreover, the provision. of a separate ringing key for useafter selection has been made necessitates an additional operation onthe part of the operator, with consequent waste of time. I simplify thekey by doing away with this main rin in kc T and erformin its tune-- D b7 I D tion incidentally in the use of the selective keys. Again, in thepresent type of keys where amechanical catch is employed for theselective keys, if it should happen that more than one key becomescaught at the same time the latch. must be thrown back by means separatefrom the keys themselves,

which requires either a separate projecting arm or lever accessible fromthe top of the key shelf, or that the shelf be lifted up or opened toget at the key from beneath. Ac-

cording to my present invention, I provide means whereby, after a key isdepressed, it is held by the latch in an intermediate position, and byfurther depressing it the latch will be released, thereby releasing anyother key which it is not desired to hold.

The primary object of the multiplicity of series contacts in some of theolder keys, is to open the generator circuit back of any individual orselective key, to prevent sending ringing current from severalgenerators to line, i more than one plunger, or button, is accidentallydepressed at the same time. In some systems, this trouble would causemore than one hell to ring on the line? By a simple modification of mypresent key, which I shall describe, the same'serics arrangement can'beemployed for cutting off, withoutthe introduction of more than twocontacts in the metallic talking circuit. This precaution-is notnecessary in a harmonic system empioying different frequencies to ringbridged bells. number of ringing springs from twenty four in oldstandard keys to thirteen in my new The cutting down of,the

key, not only simplifies the circuits and re-- duces the cost ofmanufacturing, but reduces the chances for trouble and the cost ofmaintenance. The last two points are vital from the operatingstandpoint, the first two Lila y? being actuated by a projecting lingeron the latch plate, so that when any selective key is depressed to thefullest extent, the main ey is also actuated. The main rin key contactsare located on the end of the frame, and the latter is mounted on thekey shelf with this end to the front. As all the ri key contacts arevisible at the front ends or the frames, and as these are the onlycontactsin the talking circuit, it follows that all talking circuitcontacts can be inspected by merely lifting up the key shelf.

The rel ated by a spring which also serves as a lock hold it inposition. Theframe can be emoved by pressing this springout of en- ;ocinent with a small lug .located on the frame, allowing the latter to bemoved to one side to clear its pivot.

My inverion is illustrated in the accompanying drawings wherein Figure lis side view of my improved selective key witlrparts inv section. Fig. 2is a similar View from the other side to that ,shown in Fig. I. Fig. 3is an end view showing the main ringing key contacts, and il is atransverse section through one of the plungers in i l b. l or 2. Fig. 5a diagram of the k y circuit for the key as shown in the precedingfigures, while lfig'. 6 is a. diagram of a slightly modified circuithaving series cut oil keys. Fig. 7 is a jack and line circuit diagram,showing four stations with bridged bells.

Peferring to Figs. 1, 2, 8, and 4, A is the top plate of the key frame,which I have shown faced with hard ru bber on a metal underplate c. Thistop plate is let into the top of the key shelf transversely thereto withthe end A" in front, and the frame B pro jcctingdown through the shelf.This frame consists of side members or posts 5, b, secured at theirupper ends to the top plate (1., and connected at their lower ends bythe bar B, which is composed. of a body of hard rubber Z2 faced withmetal side plates b secured together by screws [1 extending through fromone plate to the other. The rubber strip 0 is drilled at 7), b [1 and l)to receive the lower ends of the plungers c, c, c, and a, respectively.The upper ends of these plungers work in corresponding openings in thetop plate, each being littcd with a push but ton U, t or These buttonsmay he of diil'ercnt colors, if desired. About midway of its length e; hplunger has a )OlllOll of increased diameter, with a cross slot 0extending through it. in each of these slots a friction roller ispivoted, the roller being of hardened fiber, and the plvot a casehardened steel screw, whose tip end serves as a catch pin to hold theplunger down, as will be explained hereafter. 'lhese screws are shown.at a and above hem are shown twin screws 0, somewhat longer than thescrews 0 and e frame, or latch plate, is actuseason whose tips alsoserve to control the latch plate P. Each plunger is normally thrown upinto inactive position by a coil spring 0 The rubber strip 6 hastransverse slots out in it corresponding to and slightly removed fromthe openings 1;, etc, and in these slots are set the springs s, s, withinterposed slips of insulation, An overlying strip of insulation is thenlaid along the side of the main. strip, and the metal side strip l)placed upon this, holding the springs all in place. These sprin s extendup in pairs corresponding to L16 pl u ngers, the one s in each caseconstituting an anvil upon which its com anion 8 comes down when itsplunger is epressed. The u )per end of this companion spring is formedwith a projecting portion 8 normally lying below the friction. roller ofits plunger, which is partly cut away so as not to make contact with thespring. The upper end of the spring extends over and rests upon theroller at all times.

In order that the plungers may not rotate in their bearings, but maykeep the rollers and the pins in line with their cooperating parts, aguide plate G is provided secured to the underside of the. top plate bylugs g, and having slots g in which the pins 0 work up and down.

Pivotcd to the end post I) by pivot-pins p, is the latch plate l havinga ringing linger p extending out from one end of its body and bent over,as shown at p in Fig. 3, so that its extremity will engage the ringingkey springs. The plate is cut away at p, 1), p and p to forrnopcningswhich will take in the )ins 0'' when the lungers are depressed. T-'eupper edge of these openings at 29 engages with the pins when they aredown, and the cam surface p is acted upon by the pins as they pass downto throw the plate P back. it is to be observed that the pins 6 willlatch under the edge p before the plungers reach the lowermost position,and that a further movement of any plunger brings the pin 0 against thecam-plate p to force the plate P farther back than before. This extrememovement of the plate throws over the extension finger 7) far enough toactuate the ringing key B. This main controlling key R comprises the s)rings 1', r, "r 1, and r all set into the end of the rubber strip 5 andheld in place by the screw 5 The springs r, and r are stiffened by anintermediate strip of insulation, so as to form contact anvils withwhich cooperate the other springs. Springs 7" and 1" are connected by aninsulating stud 7, whose head. lies on the out ide of the spring 1' andso insulates it from the finger p NVhen the finger is moved to theright, as shown in Fig. 3, t 1e springs r, r and r 7" are separated,spring 7' being then connected with the genorator spring contact 1*. Inother words, the two sides of line are broken, and the cnerator isconnected to the forward end 0 one of ,130

25 -ter first.

( jack, through t ssr,

outwardly against the lower edge of the plate IP, and prevents alongitudinal movement thereof (or end play) by ci'igagingwith a smallinturned finger 1) formed up on the edge of the plate. The upper end ofthe s ring P is screwed or otherwise secured. to

t is post l), audit is evident that by merely pushing in the spring toclear the finger p", the plate P may be shifted 'endwise and removed.

Referrin tothe circuit dia rams Fl s. 5 b

6, and 7, the first two show c rd'cir'cuits with to, and Fig. 7 shows aline ClICulbf/O coo erate therewith. I will briefly describe the at- Theline wires 5 and 6 passto contact s rings or armatures a controlled by.the cut-o magnet U, being normally connected to line signaling devices.The magnet wind-' ing is connected to the sleeve 7' of the jack J,

keys such as'I have described, applied there whose spring 7' goesto onecontact, and the sleeve 7' to the other of a air closed to line by themagnet U when the atter becomes energized. Bridged across the line arefour ringers Q, Q, Q and Q, each in series with a suitable condenser,and all supposed to be located at different stations.

Referring to Fig. 5, which is my preferred form of key-circuit, 1 and 2are the cord con ductors of an operators set, with extensions.

3, 4 through the ringing key R to the plug T,

the latter having tip and sleeve contacts I and t to cooperate with thetwo contactsy" and j of the jack. In the ringing key, the sprin s r 7*normally complete the cord circuit or talking purposes through thecontacts 1*, 1. The contact 1 is connected. to a generator or batteryNpthrough a resistance r fin iorder to furnish current through thesleeve of the plug and the sleeve of the jack .50 to the magnet U toenergize the latter while ringing, ringing current itself not always being suitable for this'purpose, as it permits chattering and uncertaintyof contacts. The s rings 8 are the moving contact springs of t eindividual selective keys C, t), etc.

When one of these is moved over against its contact 8 it connects theindividual generator M betwc'enthe ground and the conductor 3, thence tothe ti lp t, and when. the plug is in 1e spring 3' and armature a,

over line wire 5 to, say, the first ringer Q for operative purposes,back by line wire 6 through the sleeves t and 2 to conductor 4,

spring 2*, point aresistancc r battery LN,

ground, and back to the generator M. The lamp resistances Z preventtrouble from short circuiting when more than one plunger is accidentallydepressed.

Referring to Fig. 6, I have shown the same number of generators, thesame lamp resistances, and the same ringing key connections, but insteadof connecting all the springs s in parallel along the con uctor 3, Iconnect them in series through back contacts 8 with a series of shortconnectin links 8, 9, and 10, so that if the plungers C or C are usedthey will cut off all previous plungers in the series, and make itpractically im-;

possible to put two generators to line at the same time. The conductor 3111 this case 1s connected to the last spring only, and itshould bespecially noted that even with this circuit .1 have onl the two contactsat r, 1' in the metallic tal 'ing circuit.

In operation, my key mechanism works as follows: When any plunger isdepressed its projecting in c firststrikes the cam surface p on the pate P and throws the latter back against the s ring P. The movementcontinues until t 1e pin 0 has passed down under the'edge 19, all otherpins in the meantime having been released if any were caught.

The spring 8 has been forced against its companion s by this movement ofthe plunger,

and so remains until the latter is released, when the roller 0 ispermitted to move up when the 1pin c rsts against theedge p" to separatet e springs, but still retain the key in the position shown at C in Fig.l, as an indication to the operator of the line called. In ringing, theoperator presses the key all the way down, and n so doing the pin 0comes against the cam p and carries over the finger p -to work thecontrolling kc break the cord circuit, as before, escribe'd. \Vhen thekey is released, the continuityof the circuit is restored automatically.

R and Most of the features of my improvedkey can be ap lied to existingforms 0 key, not-ablythe re easing device consisting of the sec-- ondpin a acting on the cam 19%.; If more than one key becomes caught byaccident, or

for any other reason it is desirable to .force back the latch late, itis'only necessary to push down one ey to its final limit, and byreleasing the key very quickly it is'eyenpossible to prevent catchingitselflalthough usually l adiust the keys toprevent this, oertainty ofatching being desirable.

I am quite well aware that changes and modifications may be made as todetails in the apparatus incircuit presented herewith, and I thereforewish itunderstood that I do not limit myself Yto the specific formdescribed, but wish to include all such modifications and changes as donot depart from the spirit of the invention.

. Having thus described my invention,

